A Cu(I)-based Fenton-like agent inducing mitochondrial damage for photo-assisted enhanced chemodynamic therapy.

Increasing the reactive oxygen species (ROS) content at the tumor site is one of the effective strategies to promote intracellular oxidative stress and improve therapeutic efficiency. Herein, an atomically precise cinnamaldehyde-derived metal-organic Cu(I) complex (denoted as DC-OD-Cu) was rationally constructed. DC-OD-Cu could preferentially accumulate in the mitochondria of HeLa cells due to the mitochondria-targeting ability of triphenylphosphine, which was accompanied by the generation of large amounts of highly toxic hydroxyl radicals (˙OH) via Cu(I)-mediated Fenton-like reactions. Meanwhile, greater ROS generation jointly results in mitochondrial damage under white LED light irradiation. Furthermore, the in vitro and in vivo results suggested that DC-OD-Cu possesses favorable cytotoxicity and inhibits tumor growth. We believe that this research might provide a controllable strategy to construct multifunctional metal organic complexes for ROS-involved CDT.

A triphenylphosphine coordinated cinnamaldehyde-derived copper(I) Fenton-like agent with mitochondrial aggregation damage for chemodynamic therapy.

Chemodynamic therapy (CDT), which uses agents to induce cell death by decomposing endogenous hydrogen peroxide (H2O2) into highly toxic hydroxyl radicals (˙OH), has been recognized as a promising approach to treat cancer. However, improving the efficiency of ˙OH production is considered one of the biggest challenges that limits the therapeutic efficacy of CDT. Herein, to controllably and efficiently induce oxidative damage through the production of ˙OH, we developed a new metal complex CDT agent with atomically precise structural characteristics as a deviation from traditional nanomaterial-CDT agents. The obtained CDT agent, a cinnamaldehyde derived copper(I) complex (denoted Cin-OD-Cu), was found to be continuously enriched in the mitochondria of A2780 ovarian carcinoma cells, which was accompanied by the generation of large amounts of ˙OH via Cu(I)-mediated Fenton-like reactions of H2O2, thereby stimulating oxidative stress in the mitochondria and eventually leading to cell death. Moreover, in vivo experiments showed that Cin-OD-Cu was capable of effectively inhibiting tumor growth with excellent biocompatibility. We believe this research enriches the limited selection of atomically precise metal complex CDT agents in particular for reactive oxygen species-mediated treatments aimed at inducing mitochondria oxidative damage; we anticipate that it will provide new insights into the development of novel, atomically precise agents for CDT.

[Neurological protection effects of "paraplegia-triple-needling method" on rats with incomplete spinal cord injury].

OBJECTIVE: To observe the neurological protection effects of "paraplegia-triple-needling method" on rats with incomplete spinal cord injury (SCI), so as to make a preliminary exploration on its mechanism. METHODS: A total of 45 SD rats were randomly divided into a paraplegia-triple-needling method group (group A), a regular acupuncture group (group B) and a model group (group C), 15 rats in each one. The rats model of incomplete spinal cord injury was established by modified Allen's method. The acupoints of governor vessel and back-shu points next to the vertebras of upper end and lower end of injured segment as well as motor points in key muscle of lower extremities were treated with acupuncture in the group A; the acupoints of governor vessel and back-shu points next to the vertebras of upper end and lower end of injured segment as well as "Huantiao" (GB 30), "Housanli" (ST 36), "Yanglingquan" (GB 34) and "Genduan"(Extra) were treated with acupuncture in the group B; rats in the group C received no treatment after model establishment but grabbing and immobilization. The needles were retained for 15 min in the group A and group B, once a day for 14 times. 1 d, 7 d and 14 d after model establishment, Basso Beattie Bresnahan (BBB) scores were observed in each group; the morphologic change of injured spinal cord and expression of positive cells of calcitonin gene-related peptide (CGRP) were observed. Results (1) One day after SCI, there was no significant difference of BBB scores among three groups (P> 0. 05); 7 days and 14 days after SCI, BBB scores in the group A and group B were significantly superior to those in the group C (all P<0. 05), and the BBB scores in the group A were superior to those in the group B ( both P<0. 05). (2) There was expression of CGRP positive cells in all three groups, and that in the group A and group B was significantly higher than that in group C (both P<0. 05); 14 days after treatment, the expression in the group A was higher than that in the group B (P<0. 05). CONCLUSION: The "paraplegia-triple-needling method" could obviously! improve the motor function of rats with SCI, especially the expression of neuroprotective factor CGRP, which is likely to be one of the mechanisms of neurological protection effect.